This disclosure is directed to a mold assembly, and particularly a closing assembly for molded components formed therein. The disclosure finds particular application in the manufacture of injection molded, hinged components such as hinged caps or assemblies that are generally known in the art, although it may find application in related uses.
Commonly owned US published application US 2011/0168661 is directed to a hinged cap assembly or flip cap assembly commonly used to selectively close and dispense contents from a fluid bottle or container. The disclosure of the US 2011/0168661 application is expressly incorporated herein by reference. These types of cap assemblies are typically formed of a molded plastic such as a high density polyethylene. The cap is subsequently assembled, e.g., threaded, on to a separately molded bottle. More specifically, the hinged cap assembly includes a lid hinged to a body or base member that preferably includes thread portions for threaded receipt on the corresponding threads of the bottle. By opening the lid, access is provided to a removable panel portion in the body. The panel portion is removed and the contents may be poured from the bottle. Once dispensing is complete, the lid is closed over opening in the base by pivoting the lid along the hinge. In this manner, the opening in the cap is effectively sealed by the lid.
Known equipment injection molds the cap assembly in a cavity in a manner where the base and the lid are removed from the mold cavity in an open position. That is, the lid and base of the cap assembly are usually disposed in hinged, side-by-side relation. The cap assembly is transferred to additional equipment such as a robot which folds the lid to a closed position relative to the base. The integrally molded hinge allows the lid to be pivoted about the hinge axis to a closed position where the lid snap fits to the base of the cap assembly. As will be appreciated, the additional equipment required to close the cap assembly after removal from the mold is quite expensive. The system also requires additional handling of the cap assembly, e.g., an intermediate transfer from the injection mold cavity, to the cap closure equipment, and subsequently to installation on the bottle.
A primary reason for using additional equipment to close the cap assembly is due to the fact that a thread or thread portion is integrally formed in the cap base. This requires the base of the cap assembly to be stripped, i.e. forcibly removed in an axial direction, over the thread core. This stripping action distorts the shape of the base of the cap assembly and therefore precludes closing of the lid prior to removal from the mold cavity.
In other instances, the base of the cap assembly can be removed from the thread core by rotating the cap assembly relative to the core. This presents additional challenges and expense.
The cost of separate equipment, additional handling, maintenance, etc. leads to a desire to simplify the method of manufacture and the associated equipment used to manufacture hinged cap assemblies, for example.